Tumblr is asking its iPhone and iPad users to update their applications and change their passwords after admitting it has suffered a security lapse.

In a very short post on its staff Tumblr, the company's vice-president of product Derek Gottfrid said that customers who have been using either of its iPhone or iPad apps should update their password on Tumblr and anywhere else that they have used the same one.

A spokesperson for the company told ZDNet that it was only notified of the security vulnerability in its iOS app earlier today.

"We immediately released an update that repairs the issue, and are notifying affected users. We obviously take these incidents very seriously, and deeply regret this error," the company said.

No further details on what information was potentially compromised have been made available.

Version 3.4.1 of Tumblr's app has been described by Gottfrid as a "very important security update", and the patch notes on the Apple Store only state that it is a "security fix".

The lapse in security does not appear to affect the Android or web-based versions of Tumblr at this point in time.